Question: when you grow older, how does your hair change colour i.e grey, or white

Eleanor Parker answered on 10 Mar 2014:

Hi Sophiejacko,
All hair is actually white but it is full of a protein called melanin which is what gives it colour. There are different types of melanin and people have them in different amounts which is what gives us all different hair colours. As we get older the cells that make melanin (melanocytes) make less and less util they stop making any so our hair becomes grey/white. No-one really knows for sure exactly why the cells stop making melanin but most people think there is a kind of clock in the cells which slows down as we get older and stops the cells making the melanin.